Despite several reports on using silica hollow spheres as ultrasound contrast agents, they all suffer from their inherent drawbacks, e.g., poor imaging ability caused by highly rigid shell or large particles size that leads to failures of these particles in entering tumor tissues, no mesoporous channels to load other active molecules (e.g., fluorocarbons). In this report, amino groups-functionalized hollow colloidal organosilica nanospheres (HCONs) with approximately 260 nm in diameter are prepared. Depending on the thin and pure organosilica shell, the HCONs feature high elasticity beneficial for acquiring excellent ultrasonic imaging outcomes. Our in vitro experiment shows that the ultrasonic contrast increases 11 times and in vivo experiment also shows that the ultrasound imaging performance of tumor is improved for 1.5 times. More importantly, HCONs can load liquid perfluorohexane (PFH) capable of vaporizing into gas bubbles, which further enhance the ultrasonic imaging outcome. In addition, the organosilica nanospheres have a good biosafety, which is expected to become a new generation of ultrasound contrast agent.

中文翻译：

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具有高弹性的纳米级空心胶体有机硅纳米球，用于增强对比的肿瘤超声检查

尽管有几篇关于将二氧化硅空心球用作超声造影剂的报道，但它们都具有固有的缺点，例如，由于高刚性外壳或大颗粒尺寸导致的成像能力差，导致这些颗粒无法进入肿瘤组织，没有中孔通道。装载其他活性分子（例如碳氟化合物）。在此报告中，制备了直径约为260 nm的氨基官能化的空心胶体有机二氧化硅纳米球（HCON）。取决于薄而纯的有机硅壳，HCON具有高弹性，有利于获得出色的超声成像结果。我们的体外实验表明超声对比度提高了11倍，而体内实验还表明肿瘤的超声成像性能提高了1.5倍。更重要的是，HCON可以加载能够蒸发成气泡的液态全氟己烷（PFH），从而进一步增强超声成像的效果。另外，有机硅纳米球具有良好的生物安全性，有望成为新一代的超声造影剂。